[temporary] parameter for changing bucket size

kahypar · Sep 4, 2023 · d1e7aef · d1e7aef
1 parent f423340
commit d1e7aef
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Showing 4 changed files with 12 additions and 4 deletions.
diff --git a/mt-kahypar/io/command_line_options.cpp b/mt-kahypar/io/command_line_options.cpp
@@ -481,6 +481,10 @@ namespace mt_kahypar {
              po::value<double>((initial_partitioning ? &context.initial_partitioning.refinement.fm.unconstrained_min_improvement :
                               &context.refinement.fm.unconstrained_min_improvement))->value_name("<double>")->default_value(-1.0),
              "Switch to constrained FM if relative improvement of unconstrained FM is below this treshold.")
+            ((initial_partitioning ? "i-r-fm-unconstrained-bucket-factor" : "r-fm-unconstrained-bucket-factor"),
+             po::value<double>((initial_partitioning ? &context.initial_partitioning.refinement.fm.bucket_factor :
+                              &context.refinement.fm.bucket_factor))->value_name("<double>")->default_value(1.5),
+             "Base for exponential scaling of buckets which are used for the estimation of imbalance penalties.")
             ((initial_partitioning ? "i-r-fm-obey-minimal-parallelism" : "r-fm-obey-minimal-parallelism"),
              po::value<bool>(
                      (initial_partitioning ? &context.initial_partitioning.refinement.fm.obey_minimal_parallelism :

diff --git a/mt-kahypar/partition/context.h b/mt-kahypar/partition/context.h
@@ -171,6 +171,7 @@ struct FMParameters {
   bool activate_unconstrained_dynamically = false;
   double penalty_for_activation_test = 0.5;
   double unconstrained_min_improvement = -1.0;
+  double bucket_factor = 1.5;
 };
 
 std::ostream& operator<<(std::ostream& out, const FMParameters& params);

diff --git a/mt-kahypar/partition/refinement/fm/fm_commons.cpp b/mt-kahypar/partition/refinement/fm/fm_commons.cpp
@@ -70,6 +70,7 @@ namespace mt_kahypar {
 
   template<typename PartitionedHypergraphT>
   void UnconstrainedFMData::initialize(const Context& context, const PartitionedHypergraphT& phg) {
+    bucket_factor = context.refinement.fm.bucket_factor;
     changeNumberOfBlocks(context.partition.k);
     reset();
 

diff --git a/mt-kahypar/partition/refinement/fm/fm_commons.h b/mt-kahypar/partition/refinement/fm/fm_commons.h
@@ -157,7 +157,7 @@ struct UnconstrainedFMData {
 
   // TODO(maas): in weighted graphs the constant number of buckets might be problematic
   static constexpr BucketID NUM_BUCKETS = 16;
-  static constexpr double BUCKET_FACTOR = 1.5;
+  // static constexpr double BUCKET_FACTOR = 1.5;
   static constexpr double FALLBACK_TRESHOLD = 0.75;
 
   bool initialized = false;
@@ -167,14 +167,16 @@ struct UnconstrainedFMData {
   tbb::enumerable_thread_specific<parallel::scalable_vector<HypernodeWeight>> local_bucket_weights;
   parallel::scalable_vector<parallel::scalable_vector<HypernodeWeight>> fallback_bucket_weights;
   kahypar::ds::FastResetFlagArray<> rebalancing_nodes;
+  double bucket_factor;
 
   explicit UnconstrainedFMData():
     initialized(false),
     current_k(0),
     bucket_weights(),
     virtual_weight_delta(),
     local_bucket_weights(),
-    rebalancing_nodes() { }
+    rebalancing_nodes(),
+    bucket_factor(2.0) { }
 
   template<typename PartitionedHypergraphT>
   void initialize(const Context& context, const PartitionedHypergraphT& phg);
@@ -205,7 +207,7 @@ struct UnconstrainedFMData {
   double gainPerWeightForBucket(BucketID bucketId) const {
     // TODO: test other value than 1.5
     if (bucketId > 1) {
-      return std::pow(BUCKET_FACTOR, bucketId - 2);
+      return std::pow(bucket_factor, bucketId - 2);
     } else if (bucketId == 1) {
       return 0.5;
     } else {
@@ -215,7 +217,7 @@ struct UnconstrainedFMData {
 
   BucketID bucketForGainPerWeight(double gainPerWeight) const {
     if (gainPerWeight >= 1) {
-      return 2 + std::ceil(std::log(gainPerWeight) / std::log(BUCKET_FACTOR));
+      return 2 + std::ceil(std::log(gainPerWeight) / std::log(bucket_factor));
     } else if (gainPerWeight > 0.5) {
       return 2;
     } else if (gainPerWeight > 0) {